Health literacy in asthma and chronic obstructive pulmonary disease (COPD) care: a narrative review and future directions

Respiratory self-care places considerable demands on patients with chronic airways disease (AD), as they must obtain, understand and apply information required to follow their complex treatment plans. If clinical and lifestyle information overwhelms patients’ HL capacities, it reduces their ability to self-manage. This review outlines important societal, individual, and healthcare system factors that influence disease management and outcomes among patients with asthma and chronic obstructive pulmonary disease (COPD)—the two most common ADs. For this review, we undertook a comprehensive literature search, conducted reference list searches from prior HL-related publications, and added insights from international researchers and scientists with an interest in HL. We identified methodological limitations in currently available HL measurement tools in respiratory care. We also summarized the issues contributing to low HL and system-level cultural incompetency that continue to be under-recognized in AD management and contribute to suboptimal patient outcomes. Given that impaired HL is not commonly recognized as an important factor in AD care, we propose a three-level patient-centered model (strategies) designed to integrate HL considerations, with the goal of enabling health systems to enhance service delivery to meet the needs of all AD patients.

outcomes [18][19][20]. Unfortunately, despite the importance of HL in self-management of chronic airway diseases (ADs) such as asthma and chronic obstructive pulmonary disease (COPD), its application in empowering AD patients to make informed decisions about their health remains limited [11,16,21].
Herein, we describe a model for respiratory patientcentered care that is culturally and HL-competent and explore the potential impact of these competencies on care delivery, individuals, and communities. Our goal was to provide a framework and practical approaches that can be applied to improve patient-centered care through HL. To achieve this, we applied insights from the literature and our own practical experiences (including work with national and international HL-focused groups) [22,23] to suggest strategies to integrate of HL and cultural competency at a system level.

Overview of health literacy
In 2000, Ratzan and Parker [24] defined HL as: "The degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions." The Canadian Expert Panel on Health Literacy (CEPHL) [25] and the Calgary Charter on Health Literacy [26] developed a model of HL which included five main domains (Table 1) and defined HL as a person's capability to obtain, understand, communicate, evaluate, and use health information to make appropriate healthrelated decisions". The importance of HL for each of these domains has been well established individually [27,28], and the "five-domain model of HL" has been endorsed and approved by different HL researchers and experts, as essential skills that a person may require to effectively navigate and obtain health information and care services related to their health issues [29,30]. In addition, an individual's ability to understand and calculate numerical information ("numeracy") ( Table 1) [31] is a necessary skill for an individual to understand and apply information provided in the health care system. Historically, researchers have considered numeracy to be a HL skill individually [32], however, since numeracy is a variable that is applicable to all core 5 HL domains [33], many researchers assess it across the domains rather than independently [33,34]. HL is now considered a major determinant of overall health [27,[35][36][37][38], and an essential life skill [37,[39][40][41]. HL is also viewed through a population health lens, as health literate individuals improve the overall health of a community [42,43]; and as a component of social capital, with low HL contributing to health inequalities [44]. Finally, low HL is associated with increased health care costs [45,46]. This recognition of the importance of HL has since led to development and testing of several HL measurement tools [47][48][49] for use in healthcare settings: i. the Rapid Estimate of Adult Literacy in Medicine (REALM)-a word-recognition assessment [50]; ii. the Test of Functional Health Literacy in Adults (TOFHLA)-involving reading appointment slips, interpreting prescriptions, and filling in missing words on a consent form [51]; iii. the Wide Range Achievement Test (WRAT)assessing reading recognition, spelling and basic math skills [52]; and iv. the Newest Vital Sign (NVS)-assessing reading and numeracy skills through nutrition labels [53].
These tools are brief and relatively easy to administer [54,55], and previous authors have demonstrated relationships between HL scores on these instruments and outcomes such as disease knowledge, health prevention behaviors, and quality of life, across population groups [56][57][58][59][60]. Accordingly, some have encouraged their use in practice [61,62]. However, these tools have also been criticized [17,48,54,55] for their focus on general literacy skills [27,35] rather than skills that define a health literate individual, including navigation, comprehension, motivation and activation, and self-efficacy [16,63]. In addition, these instruments were developed for the general population, rather than for specific disease groups (which may have disparate needs), and with little or no patient input [48,64]. Accordingly, many have argued that these existing HL measurement tools have limited validity and applicability in real-world healthcare settings [26,34,[65][66][67] and emphasized the need for tailored approaches to measuring HL in specific disease populations [28,[36][37][38][39]. Although various such function-based HL measures have since emerged [68][69][70][71][72], their use has not yet been reported in patients with AD. To address this, we brought together patients, HL researchers, and respiratory care clinicians to develop a new functionbased HL measurement tool (using realistic case scenarios) exclusively for asthma and COPD patients [68,[73][74][75][76][77], which is currently being validated [78].

Health literacy in respiratory care-an under-recognized problem
Asthma and COPD are among the most common chronic diseases, presenting a major and growing strain on global healthcare resources [21,46,79,80]. Patients with these conditions should be empowered to act as informed decision-makers, develop partnerships with care providers, and self-manage their condition [3,13,81]. This requires a high degree of self-efficacy, achieved by obtaining and comprehending information and instructions about their health condition and its treatment [82][83][84][85]. However, patient engagement in such decision-making is dependent on the social determinants of health, including health beliefs and practices, attitudes, cultural norms, socioeconomic status (SES), and baseline HL ( [39][40][41]86], Fig. 1).
Accordingly, providers can motivate and empower their patients to engage in disease management by improving their HL skills [83,[86][87][88][89]. The impact of improved HL skills could include slowing disease progression and improving patient-relevant health outcomes [74,[90][91][92]. Although respiratory organizations around the world have recognized the importance of addressing low HL [93][94][95][96][97][98][99] and several AD studies have administered HL measurement instruments, most of these tools focused merely on patient capabilities [8,15,16,46,100,101], and were not specific to AD populations [16,64,72,76,100], thereby, limiting understanding of the impact of low HL on AD health outcomes [14,15,67,102]. Prior investigators have suggested strategies to improve care for patients with low health literacy in clinical settings [5,22,37,103] and some approaches have shown positive results in observational studies [104,105], but, most of existing studies focus narrowly on educational interventions and corresponding outcomes related to comprehension, inhaler technique, and/or disease knowledge [106][107][108][109]. A previous systematic review [64] did not identify a single AD study that applied all five components of HL as part of an intervention. To gauge the existing state of interest and knowledge surrounding HL in AD, we sought to identify prior experimental and observational studies in ADs that assessed one or more specific component of HL (accessing, communicating, understanding, evaluating, and/or using information to improve disease outcome). These results are summarized in Table 2ac, demonstrating the characteristics of each reviewed article.
Overall, we summarize 31 articles in this narrative review. None used a disease-specific HL assessment tool, and no single study applied more than three HL domains. The 'understand' aspect of HL and improving disease 'knowledge' (using knowledge questionnaires) were assessed in all 31 reviewed articles (100%). The 'use' domain of HL was identified in 25 articles (81%) of the articles. Use was simply assessed by directly assessing if participants applied the intervention in question (e.g., education) in managing their disease, improving medication adherence, and preventing exacerbations, or by indirectly assessing the impact of the intervention in improving the outcome of interest. 'Communication' was the least assessed HL domain, which was identified in only 17 (55%) of the reviewed articles, assessed by measuring the impact of communicating with a health care provider on outcomes of interest. The 'numeracy' domain was applied in only two studies (6%), which assessed understanding of numerical concepts such as dose change instructions for self-management of asthma or COPD. Lastly, 'access' and 'evaluation' domains of HL were each assessed by only one article (3%). Access was assessed by evaluating access barriers to healthcare services and relevant disease management education, and 'evaluation' was assessed by measuring patients' ability to judge the severity of disease symptoms required to initiate needed treatment according to their action plan.                       Even when HL was assessed, measurements in individual studies were limited to associations between baseline HL and trial outcomes (e.g., behavioural, healthcare services utilization, and health outcomes) among asthma and COPD patients [90][91][92]. No trial design attempted to improve HL skills through an intervention in order to measure the impact of changes in HL on patient or health system outcomes. For instance, in Azkan Ture et al. study, [110] inadequate HL was more common in patients with severe COPD than those with milder disease. Similarly, several studies demonstrated significant associations between HL and improved self-efficacy (Fan et al. [62]; Martin et al. [82]), and disease control (Wilson et al. [111]; Janson et al. [112]). Others reported correlations between baseline HL and quality of life (Goeman et al. [113]) and Thomas et al. [114]); medication adherence and use (Apter et al. [91]) and (Khdour et al. [115]); hospitalization (Wang et al. [116]), emergency department (ED) visits (Pur Ozyigit et al. [117]), and appropriate response to symptom worsening (Poureslami et al. [84]). Overall, findings consistently showed that patients with low HL skills had lower adherence to their medications and treatment plan, visited the ED more frequently, and had more asthma/COPD-related hospital admissions/ re-admissions, and more symptom flare-ups than patients with higher HL skills. Studies also showed that HL was positively correlated with improved non-medical determinants of health. For instance, Eikelenboom et al. [118] found a link between HL levels and adopting healthier nutrition and having improved patient activation levels. Other researchers found significant associations between HL skills and exercise capacity (Wang et al. [116]), smoking cessation (Efraimsson et al. [119], and medical decision making (Wang et al. [90]. Despite these promising results, the mechanisms behind the reported associations between HL and respiratory outcomes remain unclear, as we did not identify any interventional studies that sought to enhance HL and measure impact on outcomes (e.g. inhaler technique, awareness and control of symptoms, management of acute exacerbation, and proper use of healthcare services). Accordingly, the causal relationship between HL and health outcomes requires further investigation [23,101,120].

Patient HL challenges and potential respiratory care system responses
In the following section, we highlight challenges faced by patients with AD and low HL in actively engaging in

Create informed care providers (change agents)
Provide appropriate training to early-career health professionals on how to appropriately communicate with patients, actively involve patients and family members in self-management practices, and assess and improve patients' HL skills -Health system changes: Help to create a culture, organization, and mechanism to promote accessible and highquality care to all CAD patients -Community outreach: Learn how to serve the community to meet the needs of patients and their family members, including awareness of the community environment and boundaries -Self-management and decision support: Help patients to manage their own health condition and family members' health condition by making informed health decisions

Adopt telecommunication and virtual care services
Apply emerging technologies (e.g. virtual communication and care strategies) to address and overcome the disparate and inequitable access to health information and services -Continually integrate evidence-based best practices for digital technologies into respiratory care -Provide patients with multiple avenues to communicate with care providers and to participate in health activities (e.g., virtual pulmonary rehab) -Reduce inequities in remote and/or rural access to care by leveraging digital technologies -Enhance access to digital self-management tools and materials (e.g. an electronic asthma action plan)

Intensify genuine allyship with the community
Build partnerships with community stakeholders (patients, community leaders, and opinion leaders) to acknowledge the challenges faced by community members in accessing and navigating health services -Elicit challenges experienced by community members in accessing and navigating health services -Engage community members in participatory research and co-create research agendas -Develop diverse peer-support networks for patients -Create relevant, culturally and linguistically suitable educational materials with input from diverse stakeholders Improved HL and cultural competency in respiratory care

Expected Outcomes
-Culturally safe provision of care -Improved patient-provider communications and interactions -Equitable delivery of essential health services for all patients -Enhanced patient engagement and treatment adherence -Improved respiratory patient outcomes disease management, and practice-and system-level changes required to address these barriers and drive improvements in HL.

Accessing health information and services
Limited access includes both the availability and attainability of information and services [121,122]. Disadvantaged individuals experience inadequate access for several reasons [58,104]; (1) they have less regular primary care visits [11,118,123]; (2) they are more prone to accessing healthcare information from unreliable sources outside of the medical system (e.g. a friend with a "similar" health condition, family members, neighbors, or the internet) [10,23,84,102]; (3) even when referred to specialty clinics (including respiratory clinics), these settings are particularly poorly suited to offering culturally sensitive and/or same-language care to patients of diverse backgrounds [123][124][125][126][127][128].
Given that culturally matched patient-provider interactions have been shown to augment patient engagement in disease management and to improve health outcomes [125,126,129,130], healthcare systems must invest in improving competencies and diversity of personnel (language and cultural) in order to render all care services attainable to all members of the community [2,30,102,105]. This can be supplemented by provision of multi-lingual health information (written and/or electronic) that is also easily understandable and relevant across ethnicities and cultures.

Processing and understanding information and instructions
Respiratory care providers often overestimate patients' HL skills, assuming that complex instructions have been understood [32,132]. This issue is compounded by the fact that many patients with limited HL also overestimate their own ability to process and understand medical instructions [61,111,133]. In addition to verbal communication, printed disease-related educational materials are often inaccessible to low HL patients due to an inappropriately high reading grade requirement for comprehension [23,93,97,128,134] (low HL and low literacy and reading skills are closely associated [8,9,135,136]).
To address these issues, both care and accompanying educational materials must be tailored to the diverse needs and abilities of patients across different ethnic and cultural communities, ages, and socioeconomic classes [90,137,138]. A suggested approach to foster open, interactive patient-provider communication is to compliment plain language resources [56,132,139,140] with a "teach back" approach (asking the patient to repeat back what was understood), to ensure that patients have understood information correctly [141,142], stimulating dialogue and question-asking [143]. This approach has been shown to improve medication adherence and inhaler technique in AD patients [133,144,145]. Patient input in material development can help to ensure that reading levels and content are properly matched to the target audience, and optimize both content and layout, thereby enhancing understanding and uptake [118,137,144,146]. Specifically, incorporation of patient input in self-management tools for asthma and COPD augments self-management behaviors and improves outcomes, particularly in older patients [92,113,145,147].

Appraising the quality of information and care services
To optimize health outcomes, AD patients must assess the quality and credibility of health information they encounter, and its relevance to their personal health needs [23,87,148].
Lacking corresponding critical appraisal and evaluation skills has emerged as a central issue in HL research in recent years [149,150], but has barely been studied in respiratory research [66,87,149]. Accurate measurement of evaluation skills could help to identify the differences between patients' expectations and their perceptions of the services and information received [61]. This evaluation skill component of HL is understudied, particularly in AD [68,78].

Applying information to make health-related decisions
Most attention in HL research has been focused on information availability, accessibility, and comprehension (readiness, attainability, readability, and comprehensibility of health-related information) [48,58,63]. However, maintaining health requires a series of practical acts, and obtaining and understanding relevant information does not equate to using it [114,151]. Although all aspects of HL are important, the effectiveness of health information and services in changing behavior is what ultimately determines impact [17,25]. Many patients with airways diseases have high levels of knowledge about their health condition [23,120,137,148], but struggle to apply that knowledge in the disease management process [11,12,27,107,125,135]. A person's behaviours are also influenced by internal and external motivations, as well as their ability, readiness, and willingness to use the information received from care providers [19,60,102,140,147]. Additionally, factors such as beliefs and worldviews, the perceived trustworthiness and practicability/ relevance of the information, and previous experiences all effects a person's intention to apply the information [77,78,92,152]. Accordingly, patient-provider interactions must go beyond information "transfer", to facilitate behavior change [133,140]. Improving patient educational materials to include personalized instructions (both related to the behaviour itself and how to achieve the behaviour change) may empower patients with the skills needed to change [90,117,139,153]. Additionally, when appropriate, providers may augment this process by having patients practice relevant actions and procedures (and offer feedback) to compliment and reinforce verbal and written information [56,132,154].

A model for health literacy and culturally competent respiratory care
Both cultural and social factors deeply influence the way people access and navigate health information and services [2,41,127,155]. Culturally competent care systems understand and respect the health beliefs and practices of their patients, appreciate language barriers, and apply such understanding in practice [126,134,[156][157][158]. Accordingly, HL competent care facilitates equity of essential healthcare services for all community members [14,[37][38][39][40][41]103]. Increasing diversity in healthcare providers themselves (including in leadership and governance) and use of patient navigators (trained health workers) to assist vulnerable patients with language and/ or literacy barriers may help to address system inequities [102,159]. However, implementation of these strategies may be hindered by various countries' population structures (i.e. a lack of sufficient representatives to play these roles across diverse cultural and language groups) [134,160].

A three-level model
Patients with AD, particularly older patients and COPD patients are among population groups with the lowest HL levels [92,145,147]. To achieve the goal of creating a responsive, patient-centered system of care for AD patients, we propose new strategies, in a three-level model format (Fig. 1), with special focus on training and empowering healthcare professionals to excel in roles as change agents for bridging cultural and HL gaps in their own patients [161]. The change agents can also leverage rapidly accelerating virtual care and communication technologies to address inequitable access to health information and care; and the last is to broaden the healthcare services team by building partnerships with (culturally competent) community stakeholders [162,163]. We applied the three-level model strategies in our recent research projects [10,15,68,84,125,128,130,146,164,165]. The results of our studies demonstrated potential efficacy of the proposed strategies and the need for further prospective validation. These strategies and their expected outcomes are outlined below.
Firstly, respiratory clinics should train providers to recognize the heterogeneity in patients' beliefs, preferences, limits, and needs, and consider these in their communication style and clinical practices [102,157,162,163].
There is evidence that improved provider communication skills and awareness of social determinants of health mitigate impacts of limited HL and cultural mismatch [86,157,166]. With appropriate training (in university for future health professionals and through ongoing/ continued education for current staff ), respiratory health professionals can acquire the skills required to act as change agents [167], by engaging in patient questions, explaining treatment instructions while avoiding medical jargon, and using strategies such as the teach-back method [108,140,166]. The focus of a change agent is to improve a patient's capacity and motivation to engage in self-management (one of the foundational components of AD management). Given the impact of social determinants of health [161], this role may extend beyond medical practice to a global assessment and support of financial and social factors impacting adherence, motivation, and treatment response [102,168]. This approach has been shown to improve self-management and outcomes in this population [3,88,89,92,145,154]. However, a sustainable model will require advocacy regarding the importance of non-medical determinants of health in respiratory disease management [169] to ensure that these aspects are included in future curricula and programming, and receive sufficient funding.
Secondly, to address disparate and inequitable access to health information and services, respiratory care providers must espouse emerging technology, in the form of virtual communication and care strategies. The goal is to overcome care access barriers related specifically to patients living in remote or rural areas and/or having difficulties securing time away from work for appointments during normal office hours [121,164,[170][171][172][173]. With technological advancements as well as increased provider and patient acceptance of and access to remote communication models driven by the COVID-19 pandemic [174,175] (even among lower socioeconomic class groups), telehealth can now be used to address essential healthcare services across patient populations [173]. It can also facilitate health education for patients and communication between primary care physicians and specialists [176,177]. Although telehealth-based interventions improved knowledge [176], emotional and mental health [173], quality of life [172], medication adherence [178], hospitalization and emergency department (ED) visits [179], and self-monitoring [176,178] across chronic diseases, there are no high-quality studies evaluating this in AD [177]. Ideas such as an electronically accessible action plan with weekly text message reminders to assess one's asthma control [165], and virtual pulmonary rehabilitation (PR) (telerehab) [172,180] hold promise [181]. For example, a telerehab program can provide educational materials online, with the patient attending practical sessions (e.g., exercise, breathing/cough control training) via interactive video conferencing [180,181]. Such a program was shown to improve exercise capacity, health related quality of life, and psychological status [180,181]. This approach also enables access for those living in remote locations and whose physical limitations and/or capacity to secure transit impairs in-person attendance [180]. In fact, virtual care is often favored by patients and providers alike due to convenience and flexibility [174].
Finally, a successful model must build partnerships with community stakeholders (patients, community leaders, and opinion leaders). Partnerships lead to allyship-through insights into the challenges faced by community members in accessing and navigating health services [82,118]. This can occur as part of community care, or, for example, community AD patients might be involved in participatory research (from the beginning of the research process) and/or in developing educational material [82,118,131,164]. For example, we successfully gauged AD patients' research priorities through a series of focus groups across Canada [10,73,84,146,182] and applied these in the Canadian Respiratory Research Network's research prioritization exercise (https:// respi rator yrese archn etwork. ca/). We also engaged patients, community healthcare providers, and clinicians in developing audio-visual educational materials on AD topics in seven different languages [125,128,130,163,183]. This work enabled us to establish a peer-support network [127] that offers newly diagnosed patients with AD the opportunity to gain insights from those with lived experience in managing AD [184,185]. These groups also provided an opportunity for individuals of diverse cultural backgrounds and HL levels to interact with others in a familiar language and at a comparable level of sophistication. Such peer support and patient networks have been shown to reduce patients' feelings of isolation and fear, to enhance their mental capacity to cope with their condition, and to build the confidence needed to engage in self-management [132,[184][185][186]. Care system-community collaboration has also been shown to facilitate delivery of effective education to disadvantaged patients [1,11,68,111,185,187,188].

Conclusions
As patients with AD are increasingly expected to actively engage in disease self-management, we must acknowledge the responsibility of the health system to ensure that they have the capacity to execute such complex tasks, by addressing their HL [30,37,41,105,171]. A respiratory care system that reinforces HL in a culturally competent way will improve health outcomes through patient engagement, clearer communication, and improved patient-provider interactions. Key components of system change include training healthcare providers to become change agents, accelerating adoption of evidence-based virtual communication and care strategies, and building partnerships with community stakeholders. These changes will reduce sociocultural and socio-economic disparities in care access and quality, yielding enormous benefits for patient outcomes, possibly with reductions in healthcare costs [46].
There are exciting research opportunities to design and evaluate novel strategies to both measure HL and to address cultural competency and HL in patients with AD. Longitudinal research is particularly needed to evaluate which health outcomes are improved by addressing HL in a culturally competent way, including the sustainability of observed effects. As communication technologies continually advance, research is also needed to determine the most efficient and effective strategies to enable virtual care. Ultimately, our common goal should be to realize a patient-centered respiratory care system that engages willing patients not only in decision-making around their own care, but also in the development of the very educational material that is presented to them and the very research, which establishes their therapy.